Nocturnal subcutaneous hyperaemia in the lower leg and foot of type 1 diabetic patients.

Nocturnal fluctuations in subcutaneous blood flow in the lower leg and foot were measured during sleep in Type 1 diabetic patients without autonomic neuropathy. Subcutaneous blood flow was measured, simultaneously, 100 mm above the malleolus on the medial aspect of the right lower leg and at the dorsum of the left foot in 10 diabetic patients, and on the right lower leg only in 10 normal human subjects over 12-20 h. The 133Xe wash-out technique, portable CdTe (Cl) detectors and a portable data storage unit were used. The tracer depots were applied by means of the epicutaneous, atraumatic labelling technique. In diabetic patients, subcutaneous blood flow increased 102 +/- 68% in the lower leg and 111 +/- 98% in the foot at 113 +/- 32 min and 107 +/- 37 min, after going to sleep. The hyperaemic phase lasted 128 +/- 43 min and 150 +/- 42 min, respectively. The hyperaemic response was not different from that in the control subjects (89 +/- 61%). There was no significant correlation between the absolute hyperaemia in the leg and that in the foot. In conclusion, Type 1 diabetic patients without autonomic neuropathy have normal nocturnal hyperaemia during sleep.